This invention relates to apparatus wherein droplets of ink are ejected from an orifice of an ink jet, and more particularly, to the manner in which transducers which control the ejection of droplets from an orifice are supported.
Copending application Ser. No. 336,603, filed Jan. 4, 1982 discloses an ink jet apparatus comprising an array of demand or impulse jets wherein each jet ejects a droplet of ink from an orifice in response to the expansion and contraction of elongated transducers which are energized in response to a field selectively applied transversely to the axis of elongation. As a result, substantial displacement of the transducers is achieved which is capable of ejecting a droplet of ink using relatively low drive voltages across the transducer thus minimizing the risk of electrical cross-talk between ink jets in the array. However, mechanical cross-talk can result due to the extensive contact between the transducer and the structure which supports the transducer.
U.S. Pat. No. 4,072,959--Elmquist discloses elongated transducer segments which are driven by applying a voltage transversely to the axis of elongation. Ends of the elongated transducer segments are integrally joined so as to create a substantial potential for mechanical cross-talk through the transducer itself. Moreover, the transducer segments are all immersed in an ink reservoir so as to provide substantial potential for fluidic cross-talk through the ink itself.
In addition to the problems of cross-talk addressed in the foregoing, it is important that the manner in which the transducers are supported permit a freedom of longitudinal displacement along the axis of elongation of the transducers. If such displacement is impeded, higher voltages will, of course, be necessary to drive the transducers and this, in turn, will produce electrical cross-talk. At the same time, it is important that the transducers be supported in such a way so as to permit a precision in longitudinal displacement which is coupled into the ink jet chambers which can be readily coupled into the ink jet chambers to eject droplets of ink. Moreover, it is desirable to provide support for the transducers while still permitting ease of assembly.